Chinese state media say 21 missing miners who were trapped in an August mine collapse in eastern China have been confirmed dead, bringing the death toll to 27.

The official Xinhua News Agency reported Wednesday that an explosion ripped through the Dongfang coal mine in the city of Huainan on Aug. 19. The search for the missing miners was hampered by collapsed shafts and gas pockets.

It said six bodies were found earlier, while 12 miners escaped.

Chinese authorities determined that the mine was operating illegally.